Integrated circuits and other semiconductor devices may be used in environments where radiation may induce a high current event. For example, an integrated circuit in outer space or in an environment exposed to nuclear radiation may experience a transient voltage spike or a transient current spike (e.g., the high current event) caused by a collision of a high energy particle, such as a high energy proton or ion associated with cosmic radiation or nuclear radiation, with the integrated circuit. When the integrated circuit includes a metal-oxide-semiconductor field-effect transistor (MOSFET) circuit, such a collision may cause the integrated circuit to “latchup” or enter a latchup state.
When the integrated circuit enters the latchup state, a low-impedance path (e.g., a short) may be created between power supply rails of the integrated circuit. The integrated circuit may transition from the latchup state to a normal operating state (e.g., the latchup state may be exited) when a magnitude of current flow through the integrated circuit no longer exceeds a latchup holding current value. If the integrated circuit remains in the latchup state for an extended time period, a latent failure may occur within the integrated circuit. A latent failure may indicate damage to the integrated circuit that does not cause an immediate error, and such damage is therefore difficult to detect. For example, a region of the integrated circuit may melt due to the current flow through the integrated circuit, but the integrated circuit may not generate a detectable error until a later time.
Some integrated circuits may use a latchup recovery circuit to detect a latchup condition and decouple the integrated circuit from one or more power supplies. After decoupling the one or more power supplies, power cycling may be performed on the one or more power supplies to reset voltage levels and to recover the integrated circuit from the latchup condition. Detecting the latchup condition and decoupling the integrated circuit from the one or more power supplies may take a time period on the order of hundreds of nanoseconds. Depending on an amount of the current flow through the integrated circuit and/or a temperature of the integrated circuit, a latent failure may occur before the integrated circuit is decoupled from the one or more power supplies. Thus, the latchup recovery circuit may not operate fast enough to prevent a latent failure from occurring within the integrated circuit. Additionally, circuit elements used to detect the latchup condition and to decouple the integrated circuit from the one or more power supplies add cost and complexity to the latchup recovery circuit.